#include "sys.h"		    
#include "rs485.h"	 
#include "delay.h"

//485接收数据缓冲区
u8        _RS485_RX_BUF[660];  	
//从485上接收到了期望的字节数
u8        _485jsok = 0; 
//期望从485上接收到的字节数
u16       _Hoped485ByteCounts = 0;
//485接收到的字节数
u8        _RS485_RX_CNT = 0;

 
 		  
  
void USART2_IRQHandler(void)
{
	u8 res;	    
 
 	if(USART_GetITStatus(USART2, USART_IT_RXNE) != RESET) //接收到数据
	{	 
	 			 
		res =USART_ReceiveData(USART2); 	//读取接收到的数据
 
			_RS485_RX_BUF[_RS485_RX_CNT]=res;		//记录接收到的值
			_RS485_RX_CNT++;						//接收数据增加1 
		 if(_RS485_RX_CNT==_Hoped485ByteCounts)
		 {
			 _485jsok=1;
     }
		 
	}  											 
} 
 										 
//初始化IO 串口2
//pclk1:PCLK1时钟频率(Mhz)
//bound:波特率	  
void RS485_Init(u32 bound)
{  
    GPIO_InitTypeDef GPIO_InitStructure;
  	USART_InitTypeDef USART_InitStructure;
 	NVIC_InitTypeDef NVIC_InitStructure;
 
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);//使能GPIOA时钟
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);//使能USART2时钟
	
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;				 //PA4端口配置
 	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; 		 //推挽输出
 	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
 	GPIO_Init(GPIOA, &GPIO_InitStructure);
 
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;	//PA2
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;	//复用推挽
    GPIO_Init(GPIOA, &GPIO_InitStructure);
   
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;//PA3
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; //浮空输入
    GPIO_Init(GPIOA, &GPIO_InitStructure);  

	RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART2,ENABLE);//复位串口2
	RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART2,DISABLE);//停止复位
 
	
 
	USART_InitStructure.USART_BaudRate = bound;//一般设置为9600;
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;//8位数据长度
	USART_InitStructure.USART_StopBits = USART_StopBits_1;//一个停止位
	USART_InitStructure.USART_Parity = USART_Parity_No;///奇偶校验位
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//无硬件数据流控制
	USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;//收发模式

    USART_Init(USART2, &USART_InitStructure); ; //初始化串口
  
	NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn; //使能串口2中断
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 3; //先占优先级2级
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //从优先级2级
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //使能外部中断通道
	NVIC_Init(&NVIC_InitStructure); //根据NVIC_InitStruct中指定的参数初始化外设NVIC寄存器
 
    USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);//开启中断
   
    USART_Cmd(USART2, ENABLE);                    //使能串口 

 

 RS485_TX_EN=0;			//默认为接收模式

  
 
}

//RS485发送len个字节.
//buf:发送区首地址
//len:发送的字节数 
void RS485_Send_Data(u8 *buf,u8 len)
{
	u8 t;
	RS485_TX_EN=1;			//设置为发送模式
  	for(t=0;t<len;t++)		//循环发送数据
	{		   
		while(USART_GetFlagStatus(USART2, USART_FLAG_TC) == RESET);	  
		USART_SendData(USART2,buf[t]);
	}	 
 
	while(USART_GetFlagStatus(USART2, USART_FLAG_TC) == RESET);		
	_RS485_RX_CNT=0;	  
	RS485_TX_EN=0;				//设置为接收模式	
}
 




















